Understanding the Basics of Microvia
For an HDI PCB, one of the most important layers in the system is the microvia. These are small interconnects that generally measure 150 μm or less. Over the years these components have become increasingly more complex, going from single levels to being stacked with multiple HDI levels. These components allow PCBs to safely handled the high density of input/output components that are required for much of the advanced technology on the market today.
Customers continue to drive the technology marketplace towards smaller, lighter, and more affordable products, which means that the circuit boards that help run them have to similarly be smaller and lighter. Microvia makes it possible for these devices to obtain the level of density of input/output required for success. Understanding the materials used in microvias
Microvias can be made from a variety of different types of materials, with the different materials impacting how they are made and used. Here are some of the most common examples.
• They can be made from non-conductive or non-copper conductive material, which will require it to be completed as a separate processing step.
• They can be made from plated closed with copper that has been electroplated
• An epoxy resin can be used to fill the microvia when the resin is used as a separate lamination step Types of microvias There are two main types of microvias as well.

• Buried microvias These microvia are designed to connect the internal layers, but they are not exposed on either side of the board.
• Blind microvias These microvias are visible from only one side of the board. How microvia are made 
Microvia are most commonly drilled by lasers. There are several different types of lasers that can be used for this type of job such as CO2 lasers and UV lasers. The CO2 lasers tend to be able to drill microvias at a much higher speed than other drilling techniques. The UV laser, on the other hand, offers extreme precision, making it more flexible with the types of technology which which it can be used.
Microvias are an important part of creating PCBs. As technology continues to make it easier for customers to get smaller and lighter gadgets, this component of the boards makes it possible for developers to increase the number of inputs and outputs. Those who regularly use this technology should familiarize themselves with how the parts work to increase their appreciation for the capabilities.